Mixed Signal Hardware Design Engineer

Apple

Given a string expression of numbers and operators, return all possible results from computing all the different possible ways to group numbers and operators. You may return the answer in any order. The test cases are generated such that the output values fit in a 32-bit integer and the number of different results does not exceed 104. For example: If the input is expression = 2-1-1 The expected output is [0,2] Because: ((2-1)-1) = 0 (2-(1-1)) = 2 If the input is expression = 23-45 The expected output is [-34,-14,-10,-10,10] Because: (2(3-(45))) = -34 ((23)-(45)) = -14 ((2(3-4))5) = -10 (2((3-4)5)) = -10 (((23)-4)5) = 10 Constraints: 1 <= expression.length <= 20 expression consists of digits and the operator '+', '-', and '*'. All the integer values in the input expression are in the range [0, 99]. The integer values in the input expression do not have a leading '-' or '+' denoting the sign.

Apple

Let's design a system for URL shortening, like TinyURL. Assume a large-scale service. Please consider the following aspects in your design: Functional Requirements: The system should generate shorter URLs (a.k.a. short links) given longer URLs. Users should be able to navigate to the original URL by entering the short link in their browser. The system should be highly available. Non-Functional Requirements: The system should have low latency for both URL shortening and redirection. Short links should be relatively short (e.g., 6-8 characters). The system should be able to handle a large number of URL shortening and redirection requests. Capacity Estimation: Assume 100 million URLs are shortened per day. Assume 1 billion URL redirections per day. Estimate storage requirements for 5 years. Design Considerations: How would you generate unique short links? What data structures and databases would you use to store the URL mappings? How would you handle collisions when generating short links? How would you optimize for low latency redirection? How would you scale the system to handle the expected traffic? Walk me through your design, explaining your choices and the trade-offs you considered. Provide diagrams where necessary to illustrate the architecture.

Apple

Let's say a developer doesn't agree that a reported bug is actually a bug. How would you handle this situation? Be specific. For example, imagine you're a QA engineer, and you find that a button on a webpage is slightly misaligned in a specific browser. You log this as a bug, but the front-end developer says it's 'within acceptable tolerances' and refuses to fix it. Or, perhaps a back-end developer claims that a specific edge-case error is so rare it's not worth the effort to address, even though you believe it violates the product's stated reliability goals. What steps would you take to resolve the disagreement while maintaining a positive working relationship and ensuring product quality? Consider the different approaches you could take based on the severity and impact of the potential bug.